Tension-releasing mechanism for sewing-machines.



- No. 665,3I5. Patented m. I, I90l.

w. w. mxou.

TENSION RELEASING MECHANISM FOR SEWING MACHINES. (Application filed Apr. 29, 1595.

(No Model.)

68-5 WW7: M 1 wllimwwuziigzom Unrrnn STATES PATENT WILLIAM W. DIXON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REEOE BUTTON HOLE MACHINE COMPANY, OF SAME PLACE AND PORT- LAND, MAINE.

TENSlON-RELEASING MECHANISM FOR SEWING-MACHINES.

SPECIFICATION formingpart of Letters Patent No. 66 5,315, dated January 1, 1901.

Application filed April 29, 1898. Serial No. 679,177. (No model.)

1'0 00M whom it may concern:

Be it known that I, WILLIAM W. DIXON, of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Tension Releases for Sewing Machines, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

In stitching buttonholes, especially in the class of machine represented in United States Patent No.- 349,359, dated September 21, 1886, it is especially desirable to leave the thread free from tension when the stitching of a buttonhole has been completed, so that the operator, the needle-thread having been cut off, may find the said thread free from tension, so that he may easily engage the cut end of the thread and draw the same through the needle, so as to insure a sufficient length of thread at one side of the eye of the needle to properly make the first stitch to be takenin the next buttonhole to be made. I have devised special mechanism for effecting this release of the needle-thread.

In my invention the stitch-frame which carries the tension device for the upper needlethread is provided with a lever to act upon a releasing-pin cooperating with the threadtension device, said lever acting at one end upon a rod held in a suitable guide on the stitch-frame, the lower end of said rod being acted upon by a projection or cam adj ustably connected with the clamp-frame, the adjustment of said cam enabling the operator to insure the release of the needle-thread tension sooner or later after the stitching of the buttonhole and preparatory to stopping the machine.

Figure 1 of the drawings represents in side elevation a sufficient portion of a sewing-machine of the class referred to with my improvements added to enable the same to be understood. Fig. 2 is aright-hand end View of the parts shown in Fig. 1. Fig. 3 shows the washer or blank removed, and Fig. 4 is a section in the line so of Fig. 1.

The stitch-frame a and clamp-frame ct are and may be all substantially as represented in said patent. The stitch-frame has erected on it a stand 19, shown as provided with a split stud c, bored throughout to receive a releasing-pin (1, said releasing-pin acting at one end against a bridge e of a washer 6', provided with two holes 6 which fit over the split portion of the releasing-pin, as at the right in Fig. 4, said washer being acted upon at one side by a suitable spiral or other spring f, in turn acted upon byan adjustable nutf', applied to the threaded portion of the said split stud. Before the washer referred to is applied to the said split stud I apply, preferably, a feltor other washer, as g, and then I apply a tension-wheel h, and against the opposite side of said tension-wheel and between it and said washer I apply a second washer g, also preferably of felt. The spring facts to restrain the rotation of the tension-wheel h, and by adjusting the spring the tension may be regulated as desired.

The releasingpin d when moved to the right in Fig. 4 removes the pressure of the washer acted upon by the spring from the tension-wheel, leaving the said tension-wheel entirely free, so that it may be easily rotated about the said split stud by any slight pull on the thread extended through the eye of the usual needle. To actuate this releasing-pin, I have mounted upon the stand I) at m a lever m, shown as of elbow shape, one extremity of the lever having an inturned lip, as m to contact with the releasing-pin. The outer end of the lever m enters a slit in the upper end of a rod 01, extended through suitable guides n of a frame n attached to the stitchframe by suitable screws M the lower end of said rod riding on a cam-block 0, adj ustably attached to the clamp-frame by suitable screws 0. The adjustment of this block enables the operator to insure the release of the needle-thread tension sooner or later after the stitching of the buttonhole and preparatory to stopping the machine.

In the operation of the machine the stitchframe is moved relative to the clamp-frame, and when the buttonhole has been finished the lower end of the rod 07. meets the cam 0 of the cam-block and turns the lever m, so

that its end m acts on the releasing-pin d and releases the tension on the needle-thread, so that said thread when out OK from the work near the eye of the needle may beeasily grasped by the fingers of the operator and be pulled freely through the eye of the needle, the tension device giving up the thread readily.

The stand near the tension-Wheel has a thread-check composed of a headed stud 19, having a hole p, said stud being surrounded by a Washer 13 acted upon by a spring 19 surrounding said stud, the action of said spring being very slight on the thread. The purpose of said check is chiefly to remove knots and enable the thread to be retained on the wheel It.

By the employment of the rod 11 and lever m between the cam 0 and the releasing-pin I am enabled to more easily move the releasing-pin, and the movement of said lever in actuating said pin has no tendency to bend or strain it.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a sewing-machine for stitching buttonholes, a stitch-frame adapted to carry stitch-forming mechanism, a clamp-frame, one of said frames being capable of movement relative to the other, a tension device carried by the stitch-frame, a lever pivotally mounted on said stitch frame, releasing means between saidlever and tension device, a rod connected with said lever, a suitable guide carried by said stitch-frame to receive and guide said rod, and a cam mounted upon said clamp-frame at the lower end of said rod, whereby the relative movement of the stitch-frame and clamp-frame causes the cam to engage the rod and release the tension on the thread.

2. In a sewing-machine for stitching buttonholes, a stitch-frame adapted to carry stitch-forming mechanism, a clamp-frame,

one of said frames being adapted for move ment relative to the other, a stand mounted on the stitch-frame, a stud carried by said I stand, a tension-wheel mounted on said stud, means to exert pressure against said tension- Wheel to put a tension on the thread extended over it, a releasing-pin, a lever, a rod against which one end of said lever rests, and a guide carried by said stitch-frame to receive said rod combined with a cam carried by the clamp-frame, whereby as the relative positions of said stitch frame and clampframe are changed, said cam acts on said rod, and through the lever operates upon the releasing-pins to effect the release of the tension on the thread.

3. In a sewing-machine for stitching buttonholes, a stitch frame adapted to carry stitch-forming mechanism, a clamp-frame, one of said frames being capable of movement relative to the other, a stand mounted on the stitch-frame, a tension-Wheel rotatably mounted on said stand, a spring-pressed friction-Washer bearing against said tensionwheel, a releasing-pin bearing against said washer, a lever pivoted on the stitch-frame and engaging the opposite end of said releasing-pin, a rod against which one end of said lever rests, and a guide carried by said stitchframe to receive said rod combined with a cam carried by the clamp-frame, whereby as the relative positions of said stitch-frame and clamp-frame are changed, the cam acting on said rod moves the lever and operates the releasing-pin to release the pressure on said friction-washer, to thereby remove the tension from the thread.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM WV. DIXON.

Witnesses:

GEO. W. GREGORY, lVIARGARET A. DUNN. 

